Methods and apparatus for transmitting data streams via a heterogeneous network

ABSTRACT

Methods and apparatus that enable a community of devices having differing underlying protocols to stream media data such as video or audio data. In one exemplary embodiment, this invention enables IEEE 1394-compliant (“FireWire” enabled) devices to communicate across an Ethernet infrastructure, such as one enabled by the Ethernet AVB Standard(s). This enhances connectivity, and also supports obviating one or more physical ports within the device(s). In another embodiment, or more wireless transports are utilized.

PRIORITY

This application is a divisional of and claims priority to co-owned,U.S. patent application Ser. No. 12/572,995 entitled “METHODS ANDAPPARATUS FOR TRANSMITTING DATA STREAMS VIA A HETEROGENEOUS NETWORK”,filed Oct. 2, 2009 (issuing as U.S. Pat. No. 8,392,631 on Mar. 5, 2013),which claims priority to U.S. Provisional Patent Application Ser. No.61/195,141 filed Oct. 2, 2008 of the same title, each of which areincorporated by reference herein in its their entirety.

COPYRIGHT

A portion of the disclosure of this patent document contains materialthat is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent files or records, but otherwise reserves all copyrightrights whatsoever.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates generally to the field of data networksand device data sharing. More particularly, in one exemplary aspect, thepresent invention is directed to methods and apparatus enabling aheterogeneous community of devices (e.g., those which operate accordingto a FireWire or Ethernet AVB protocol) to interoperate seamlessly andtransfer data and media (e.g., audio and video) there between.

2. Description of Related Technology

Modern electronic equipment has greatly enhanced the quality of life formany. However, as the use of such equipment has increased, so has theneed to connect equipment of differing types purchased from differentmanufacturers. For example, while a computer and a digital camera mayeach be useful when used alone, the ability to connect the digitalcamera to the computer and exchange information (e.g., photos, video)between the two makes the combination even more useful. Therefore, aneed was apparent for a serial bus standard that would allow for theconnection and communication between such devices.

The IEEE 1394-1995 standard (and its associated trade names “FireWire™”(Apple Inc.), “i.LINK” (Sony), and “Lynx” (Texas Instruments), etc.) wasdeveloped to satisfy this need. This standard revolutionized theconsumer electronics industry by providing a serial bus managementsystem that featured high speeds and the ability to “hot” connectequipment to the bus; that is, the ability to connect equipment withoutfirst turning off the existing connected equipment. Since its adoption,the IEEE 1394-1995 standard has seen acceptance in the marketplace withmany major electronics and computer manufacturers providing IEEE1394-1995 connections on equipment that they sell. Several variants ofIEEE 1394 have also been developed and widely deployed which improve andenhance various system characteristics (including e.g., higher speedsand longer connection paths).

In addition to IEEE 1394 based standards, a new standard being proposedat the time of the filing of the present application is herein referredto as the “Ethernet AVB standard”. Ethernet AVB is a new standard beingdeveloped for transmitting audio and video data across an 802.1 Ethernetlink. Existing Ethernet standards guarantee packet delivery; EthernetAVB is expected to provide additional capabilities enabling isochronousdata transfer. Specifically, Ethernet AVB provides guarantees on maximumlatency and minimum bandwidth that enable “streaming” applications,which were previously limited due to requirements for low latencyisochronous transfer of audio and video.

Unsatisfied Need for Interoperability

Due to the widespread existing deployments of existing IEEE 1394devices, and the virtually universal Ethernet infrastructure, a solutionfor providing interoperability for the two standards seamlessly (withrespect to various types of media) would greatly enhance the overallutility of both. Such a solution does not currently exist.

Another issue relates to the increasing “disappearance” of physicalports on hardware devices such as computers, video cameras, etc. overtime. These physical ports (including FireWire ports) are becoming lessprolific on new generation devices because, inter alia, aggressive formfactor reductions no longer allow distinct connectors for all supportedI/O technologies. Thus, physical space for the port and the extra costof the port make it a strong candidate for removal. For example, in theMacBook Air product manufactured by the Assignee hereof, connectorsinclude only a USB port, power port and a video port. Neither a physicalFireWire port nor Ethernet port are present on the device. As the numberof (FireWire and other) ports disappear, so do the connectivityopportunities for devices using that port specification. Hence, in orderto maintain FireWire support and distribution over such devices, other“ways off of” and “ways onto” the device are needed.

Accordingly, improved methods and apparatus are needed for providingdata stream delivery between two differing protocols, such as forexample Ethernet AVB, and IEEE 1394. Such an improved solution shouldoperate seamlessly and without adversely impacting user experience onexisting apparatus. Moreover, such “multi-lingual” data stream deliverywould be operable without requiring undue hardware or other modificationto implementations already deployed. To these ends, such data deliveryschemes should minimally support “master-slave” operation, where adynamically bridging multi-lingual device performs all translation forits localized network, without requiring its non-enabled slave devicesto do so.

Multiple clients would also advantageously work cooperatively tosimultaneously source and sink isochronous datastreams, eachindependently capable of additionally splitting or merging multipleisochronous data streams.

Lastly, such improved apparatus and methods would enable the use of IEEE1394-compliant devices across any geography or topology, such as bypiggybacking on existing Ethernet infrastructure.

SUMMARY OF THE INVENTION

The present invention satisfies the foregoing needs by providing, intercilia, improved apparatus and methods for bridging data (including audioand video or other multimedia data) across networks or devices usingdifferent protocols.

In one aspect of the invention, a method for sending a message from asource device to a target device is disclosed. In one embodiment, themessage is sent via a fabric or other intermediary architecture, andsaid source device operates with a first protocol, and said fabricoperates with a second protocol, said first and second protocols beingdifferent. The method comprises: associating said source device with asoftware entity; associating said target device with said softwareentity; responsive to said associations of said source device and saidtarget device, negotiating one or more parameters related to data streamrequirements; receiving at least one message compliant with said firstprotocol from said source device; formatting said at least one messagesto be compliant with said second protocol, and said negotiated one ormore parameters; and transmitting said formatted at least one messagesvia said fabric.

In one variant, said source device and fabric are characterized byisochronous transfer parameters.

In another variant, the first protocol comprises a 1394-compliantprotocol, and the second comprises an Ethernet AVB compliant protocol.

In a second aspect of the invention, a source device adapted forisochronous data transfer is disclosed.

In a third aspect of the invention, a transfer medium adapted tofacilitate media/data transfer between different protocol environmentsis disclosed. In one embodiment, the medium comprises a fabric capableof connecting 1394.1 bridge portals and that is capable of transferringany serial bus subaction from one portal to its co-portal, and thatsupports bidirectional, non-blocking transfer of asynchronous requestsubactions, asynchronous response subactions, and isochronoussubactions.

In a fourth aspect, a computer readable medium comprising at least onecomputer program adapted transfer media/data between different protocolenvironments is disclosed.

In a fifth aspect of the invention, a client device adapted to run theaforementioned program is disclosed. In one variant, the client devicecomprises a desktop or portable computer. In another variant, the clientdevice comprises a personal media device or PDA. In yet anotherembodiment, the device comprises a network router, such as a home LAN orswitch or router.

In a sixth aspect of the invention, a portal architecture is disclosed.In one embodiment, the portals comprise 1394.1-compliant portalsdisposed on each side of an Ethernet AVB network, and which employ AVCcommand interpreters. This approach allows existing FireWire software to“see” FireWire devices that are not physically connected to the localFireWire bus (or if there is no local FireWire bus at all).

In a seventh aspect of the invention, one or more wireless protocols areutilized as the bearer(s) for the transported media content.

In an eighth aspect of the invention, business models and associatedmethods of doing business are disclosed.

In a ninth aspect, a method of managing connectivity over aheterogeneous fabric is disclosed. In one exemplary embodiment, themethod includes: receiving an indication of one or more capabilitiesassociated with a first device, the first device having a first protocolassociated therewith and the first device being coupled to theheterogeneous fabric, responsive to the indication, storing at least onedevice capability associated with the first device, and responsive to areceived request for a connection to a target device, providing the atleast one stored device capability to the target device.

In a variant, the target device has a second protocol associatedtherewith.

In a tenth aspect, an apparatus configured to manage connectivity of aheterogeneous fabric is disclosed. In one embodiment, the apparatusincludes an interface, a processor, and a computer readable storagemedium.

In a variant, the computer storage medium includes instructionsconfigured to, when executed by the processor: responsive to a devicehaving a first protocol associated therewith being coupled to theheterogeneous fabric, the fabric having a second protocol different fromthe first protocol, identify one or more device capabilities, store theone or more device capabilities, and responsive to the device requestingconnection to a target device, provide the stored one or more devicecapabilities to the target device. The device and the target device inone implementation initiate a data connection via the heterogeneousfabric without further intervention by the apparatus.

In an eleventh aspect, an apparatus for interoperation with aheterogeneous fabric is disclosed. In an exemplary embodiment, theapparatus includes: an interface to the heterogeneous fabric, theheterogeneous fabric comprising multiple different device protocols, auser interface, a processor, and a computer readable apparatus having astorage medium.

In a variant, the storage medium includes a computer program configuredto, when executed by the processor, cause the apparatus to: responsiveto a connection to the heterogeneous fabric, register with a networkdaemon, identify one or more other devices connected to theheterogeneous fabric via the network daemon, and responsive to a userrequest via the user interface, initiate a data connection to at least atarget device of the one or more other devices within a user session.

Other features and advantages of the present invention will immediatelybe recognized by persons of ordinary skill in the art with reference tothe attached drawings and detailed description of exemplary embodimentsas given below—

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a logical flow diagram illustrating one embodiment of thegeneralized method of transferring data across a heterogeneous protocolenvironment according to the invention.

FIG. 2 is block diagram illustrating one embodiment of an apparatusadapted to transfer data across a heterogeneous protocol environment.

FIG. 3 is a graphical illustration of protocol stack interactionsbetween two exemplary devices as part of the data transfer of FIG. 1.

FIG. 3A is a graphical illustration of one embodiment of a data packetstructure according to the invention.

FIG. 3B is a high layer representation of one exemplary embodiment of asoftware system comprising a user and kernel space, according to thepresent invention.

FIG. 3C is a graphical representation of one embodiment of kernel spaceadditions useful for implementing the heterogeneous protocol datatransfer functionality of the present invention.

FIG. 3D is another graphical representation of various components of theprotocol stack of FIG. 3C, and their interrelationships.

FIG. 3E is a graphical representation of one embodiment of user spaceadditions useful for implementing the heterogeneous protocol datatransfer functionality of the present invention.

FIG. 3F is a block diagram of one exemplary embodiment of a softwarearchitecture employing a proxy for interfacing between a first deviceand various software processes on the same or different device, usingthe kernel space and user space components of FIGS. 3C and 3E,respectively.

FIG. 4 is a block diagram illustrating one exemplary heterogeneouscommunity of devices according to the invention.

FIGS. 5A-5D are block diagrams illustrating various different userscenarios consistent with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference is now made to the drawings, wherein like numerals refer tolike parts throughout.

As used herein, the terms “client device”, “end user device” and “userequipment” or “UE” include, but are not limited to cellular telephones,smartphones (such as for example an iPhone™), personal computers (PCs),such as for example an iMac™, Mac PrO™, Mac Mini™ or MacBook™, andminicomputers, whether desktop, laptop, or otherwise, as well as mobiledevices such as handheld computers, PDAs, video cameras, set-top boxes,personal media devices (PMDs), such as for example an iPod™, or anycombinations of the foregoing.

As used herein, the term “computer program” or “software” is meant toinclude any sequence or human or machine cognizable steps which performa function. Such program may be rendered in virtually any programminglanguage or environment including, for example, C/C++, Fortran, COBOL,PASCAL, assembly language, markup languages (e.g., HTML, SGML, XML,VoXML), and the like, as well as object-oriented environments such asthe Common Object Request Broker Architecture (CORBA), Java™ (includingJ2ME, Java Beans, etc.), Binary Runtime Environment (BREW), and thelike.

As used herein, the terms “Ethernet AVB” and “Ethernet AVB Standards”refer, without limitation, to any one or more of the following asapplicable: (i) IEEE Std. P1722; (ii) IEEE Std. P802.1AS; (iii) IEEEStd. P802.1Qat; (iv) IEEE Std. P802.1Qav; (v) IEEE Std. P802.1AB; (vi)IEEE Std P802.1BA; (vii) IEEE Std. P1722; and (viii) IEEE Std. 1394TA2006021, each of the foregoing being incorporated herein by reference inits entirety.

As used herein, the terms “IEEE 1394” and FireWire” refer withoutlimitation to any one or more of the following as applicable: (i) IEEEStd. 1394-1995; (ii) IEEE Std. 1394a-2000 amendment; (iii) IEEE Std.1394b-2002 amendment; and (iv) IEEE Std. 1394c-2006 amendment, each ofthe foregoing being incorporated herein by reference in its entirety.

As used herein, the term “integrated circuit (IC)” refers to any type ofdevice having any level of integration (including without limitationULSI, VLSI, and LSI) and irrespective of process or base materials(including, without limitation Si, SiGe, CMOS and GaAs). ICs mayinclude, for example, memory devices (e.g., DRAM, SRAM, DDRAM,EEPROM/Flash, and ROM), digital processors, SoC devices, FPGAs, ASICs,ADCs, DACs, transceivers, memory controllers, and other devices, as wellas any combinations thereof.

As used herein, the term “memory” includes any type of integratedcircuit or other storage device adapted for storing digital dataincluding, without limitation, ROM. PROM, EEPROM, DRAM, SDRAM, DDR/2SDRAM, EDO/FPMS, RLDRAM, SRAM, “flash” memory (e.g., NAND/NOR), andPSRAM.

As used herein, the terms “microprocessor” and “digital processor” aremeant generally to include all types of digital processing devicesincluding, without limitation, digital signal processors (DSPs), reducedinstruction set computers (RISC), general-purpose (CISC) processors,microprocessors, gate arrays (e.g., FPGAs), PLDs, reeonfigurable computefabrics (RCFs), array processors, secure microprocessors, andapplication-specific integrated circuits (ASICs). Such digitalprocessors may be contained on a single unitary IC die, or distributedacross multiple components.

As used herein, the terms “network” and “bearer network” refer generallyto any type of data, telecommunications or other network including,without limitation, data networks (including MANs, PANs, WANs, LANs,WLANs, micronets, piconets, internets, and intranets), hybrid fiber coax(HFC) networks, satellite networks, cellular networks, and telconetworks. Such networks or portions thereof may utilize any one or moredifferent topologies (e.g., ring, bus, star, loop, etc.), transmissionmedia (e.g., wired/RF cable, RF wireless, millimeter wave, optical,etc.) and/or communications or networking protocols (e.g., SONET,DOCSIS, IEEE Std. 802.3, 802.11, ATM, X.25, Frame Relay, 3GPP, 3GPP2,WiMAX, WAP, SIP, UDP, FTP, RTP/RTCP, H.323, etc.).

As used herein, the terms “network interface” or “interface” typicallyrefer to any signal, data, or software interface with a component,network or process including, without limitation, those of the FireWire(e.g., FW400, FW800, etc.), USB (e.g., USB2), Ethernet (e.g., 10/100,10/100/1000 (Gigabit Ethernet), 10-Gig-E, etc.), MoCA, Serial ATA (e.g.,SATA, e-SATA, SATAII), Ultra-ATA/DMA, Coaxsys (e.g., TVnet™), radiofrequency tuner (e.g., in-band or OOB, cable modem, etc.), Wi-Fi(802.11a,b,g,n), WiMAX (802.16), PAN (802.15), IrDA or other wirelessfamilies.

As used herein, the term “wireless” means any wireless signal, data,communication, or other interface including without limitation Wi-Fi(IEEE Std. 802.11), Bluetooth, 3G (3GPP, 3GPP2, UMTS), HSDPA/HSUPA,TDMA, CDMA (e.g., IS-95A, WCDMA, etc.), FHSS, DSSS, GSM, PAN (IEEE Std.802.15), WiMAX (IEEE Std. 802.16), MWBA (IEEE Std. 802.20),narrowband/FDMA, OFDM, LTE, PCS/DCS, analog cellular, CDPD, satellitesystems, millimeter wave or microwave systems, acoustic, and infrared(i.e., IrDA).

As used herein, the terms “WLAN” and “wireless LAN” refer generally toany system wherein a wireless or air interface is employed between twodevices, and which provides at least local area networking capability.Wi-Fi systems are one exemplary instance of WLANs.

Overview

In one aspect, the present invention discloses, inter alia, methods andapparatus that enable a community of heterogeneous isochronous deviceshaving differing underlying protocols to stream data such as video oraudio data. In one exemplary embodiment, this invention enables IEEE1394-compliant (“FireWire” enabled) devices to communicate across anEthernet infrastructure, such as one enabled by the recent Ethernet AVEStandard(s).

In one variant, the invention enables an IEEE 1394 device to stream datato an Ethernet AVB-compliant device (or vice versa).

In another variant, an IEEE 1394 device may stream data to another IEEE1394 device via an Ethernet AVB-compliant fabric.

In a second alternate embodiment, this invention enables IEEE1394-compliant (“FireWire” enabled) devices to communicate across awireless network infrastructure, such as one enabled by IEEE 802.11(Wireless Local Area Networks).

In another aspect, methods and apparatus are disclosed which enableflexible connection management for an isochronous system having multiplesources and targets (e.g. an audio network). In one embodiment, suchflexible connection management is provided for without regard to thedirection or distribution of datastreams.

In yet another aspect of the invention, an implementation-dependent data“fabric” is disclosed. In one embodiment, the fabric is adapted forcompliance with IEEE 1394.1 bridging requirements, and comprisesapparatus adapted to interconnect the 1394.1 bridge portals that iscapable of transferring any serial bus subaction from one portal to itsco-portal, and that supports bidirectional, non-blocking transfer ofasynchronous request subactions, asynchronous response subactions, andisochronous subactions.

In one variant, the fabric is limited in geographical extent (e.g., thebridge portals and fabric are each located within a common deviceenclosure or even on a common substrate or module within the device).

In another variant, the fabric is physically extensive (e.g., thebridge's portals are located in more disparate locations, such as inseparate rooms of a house, or even in separate buildings).

In a second alternate embodiment, the fabric is adapted for wirelessoperation. In one such embodiment, the fabric is adapted for compliancewith IEEE 802.11 (Wireless Local Area Networks).

Advantageously, the methods and apparatus of the exemplary embodiment ofthe present invention are agnostic (work with) any of the variants ofthe FireWire 1394 standard.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Exemplary embodiments of the present invention are now described indetail. While these embodiments are primarily discussed in the contextof an isochronous network of devices having differing protocols, andmore specifically to a heterogeneous network of IEEE 1394-compliant andEthernet AVB devices, it will be recognized by those of ordinary skillthat the present invention is not so limited, and in fact may be used inother types of applications, and with different protocols.

The following brief discussion of standards and their associateddescendents is useful for understanding one or more aspects of thepresent invention.

Ethernet AVB

So-called “Ethernet AVB Standards” include: (1) IEEE Std.P1722—Streaming Transport; (ii) IEEE Std. P802.1AS; (iii) IEEE Std.P802.1Qat; (iv) IEEE Std. P802.1Qav; (v) IEEE Std. P802.1AB; (vi) IEEEStd P802.1 BA; (vii) IEEE Std P802.1BA; and (viii) IEEE Std. 1394TA2006021, each of the foregoing which are incorporated herein byreference in their entirety.

IEEE 1394-1995

As of 2007, IEEE 1394 was a composite of four documents: the originalIEEE Std. 1394-1995, the IEEE Std. 1394a-2000 amendment, the IEEE Std.1394b-2002 amendment, and the IEEE Std. 1394c-2006 amendment. On Jun.12, 2008, all these amendments as well as errata and some technicalupdates were incorporated into a superseding standard IEEE Std.1394-2008.

IEEE 1394-1995 (“FireWire 400”)

FireWire 400 can transfer data between various interconnected devices atdata rates of 100, 200, or 400 Mbps half-duplex data rates (the actualtransfer rates are 98.304, 196.608, and 393.216 Mbps. These differenttransfer modes are commonly referred to as S100, S200, and S400. Underthis standard, cable length is also limited, although several cables canbe daisy-chained using repeaters, hubs, etc. often present in FireWireequipment (although there is a maximum “total” chained length limitationalso).

IEEE 1394a-2000

An amendment to the original standard (IEEE 1394a) was released in 2000which both clarified and enhanced the original specification. Supportfor asynchronous streaming was added, as was faster bus reconfiguration,packet concatenation, and a power-conserving “suspend” mode ofoperation. 1394a also standardized use of the 4-pin (non-power)connector.

IEEE 1394b-2002 (“FireWire 800”)

FireWire 800 or S800 was introduced commercially by Apple Inc. in 2003.This newer (1394b) specification allows a transfer rate of 786.432 Mbpsfull-duplex via a new encoding scheme often referred to as “beta” mode.It is backwards compatible to the slower rates of FW400 described above.However, while the IEEE 1394a and IEEE 1394b standards are compatible,FireWire 800's connector is different from FireWire 400's connector,making the cables incompatible. A “bilingual” cable is available whichallows the connection of legacy devices to the new port.

The 1394b specification supports data rates up to 3200 Mbit/s (S1600 andS3200) over beta-mode or optical connections up to 100 meters in length.Standard CAT-5e unshielded twisted pair supports 100 meters at S100. Theoriginal 1394/1394a standards used data/strobe (D/S) encoding (calledlegacy mode) on the signal wires, while 1394b added a new data encodingscheme called 8B10B,

IEEE 1394c-2006 (“FireWire S800T”)

IEEE 1394c-2006 was published on Jun. 8, 2007, and provides severalchanges including: (i) a new port specification which provides 800Mbit/s over the same RJ45 connectors with CAT-5e cable which isspecified in IEEE 802.3 clause 40 (gigabit Ethernet over copper twistedpair); (ii) automatic negotiation that allows the same port to connectto either IEEE Std 1394 (FireWire) or IEEE 802.3 (Ethernet) devices.

IEEE Std. 1394.1

FireWire bridging (IEEE 1394.1) was designed to support longer distancesand more devices on a network. Currently, 63 devices is the maximumnumber of devices allowed on a single FireWire bus. The 1394.1 bridgingallows the connection of multiple busses for expanding the number ofdevices. Also, by expanding the number of busses, the maximum distancebetween devices can be expanded as well. IEEE 1394.1 defines a “bridge”as consisting “ . . . of two bridge portals (each with its associatedPHY and link), queues (FIFOs) for asynchronous and isochronoussubactions (which collectively form an implementation-dependent fabricbetween the two portals), cycle timers, route maps, and configurationROM.” However, it is appreciated that the foregoing definition isimplementation specific, and the present invention is in no way solimited. More broadly, as used throughout, the term “bridging”,“bridge”, etc. refers to the physical and logical apparatus necessary toconnect a first network technology to a second network technology. Suchmethods and apparatus may be physical (e.g., hardware/firmwareimplementations), logical (e.g., software implementations), or anycombination thereof.

In addition to the foregoing standards and protocols, others have beenadopted (or are under development) which relate to AN transmission:

IEEE Std. 802.1Qat

IEEE Std. 802.1 Qat (“Standard for Local and Metropolitan AreaNetworks—Virtual Bridged Local Area Networks—Amendment: 9: StreamReservation Protocol (SRP)”), which is incorporated herein by referencein its entirety, provides for reservation of bandwidth on the network(including between end stations through a number of bridges). A“listener” requests bandwidth to a “talker” and bridges ask each otheralong the chain if there is sufficient bandwidth to support adding thestream.

IEEE Std. 802.1Qav

IEEE P802.1Qav (“IEEE Standard for Local and Metropolitan AreaNetworks—-Virtual Bridged Local Area Networks—Amendment: Forwarding andQueuing Enhancements for Time-Sensitive Streams”), which is incorporatedherein by reference in its entirety, specifies how to queue packets tonot burst traffic across the network. Bridges are used to automaticallyshape traffic.

IEEE Std. 802.1AB

IEEE Std. 802.1 AB (“Station and Media Access Control ConnectivityDiscovery—Apr. 5, 2005”), which is incorporated herein by reference inits entirety, discloses Link Layer capability discovery; i.e., discoveryof what capabilities the ends of the link have. This protocol may beused to tell end stations what priority to send class-A and class-Btraffic, and may be used by some bridges to enable AVB functionality.

IEEE Std P802.1BA

IEEE Std P802.1BA (“Audio Video Bridging (AVB) Systems—Draft PAR—Feb. 1,2008), which is incorporated herein by reference in its entirety,discloses profiles that select features, options, configurations,defaults, protocols and procedures of bridges, stations and LANs thatare necessary to build networks that are capable of transporting timesensitive audio and/or video data streams.

IEEE Std. 1394TA 2006021

IEEE Std. 1394TA 2006021 (“Networking IEEE 1394 Clusters via UWB overCoaxial Cable—Part 3: FCP and CMP over IPv4”), which is incorporatedherein by reference in its entirety, describes discovering andcontrolling device configurations, and connection management. It isbased on the 1394 TA Specifications, and uses (i) UDP/IP forcommunications, and (ii) Bonjour™ protocol for discovery and removalnotifications.

IEEE Std. 802.1AS and “AppleAS”

IEEE Standard 802.1AS (“IEEE Standard for Local and Metropolitan AreaNetworks—Timing and Synchronization for Time-Sensitive Applications inBridged Local Area Networks”), which is incorporated herein by referencein its entirety, provides mechanisms for synchronizing frequency ofclocks, and for measuring the propagation delay across a link. It alsoprovides a NIC-to-bridge interface in bridged network, and NIC-to-NIC ina two-machine network. It is based on IEEE 1588, and requiresingress/egress time stamping in the MAC (i.e., Sync, PDelay_Request, andPDelay_Response frames time-stamped on egress and ingress).

The AppleAS protocol is an implementation of the IEEE 802.1AS protocoldeveloped in interest of the Assignee. The functionality of AppleAS isdescribed in greater detail herein. Briefly, AppleAS comprises anabstraction layer that isolates the vendor code from differences inEthernet AVB hardware, and can still function without dedicated hardware(though at a reduced precision of time synchronization). It resolves orreconciles the IEEE 801.1 AS clock with the resident system's CPU clock,such that the software can relate system time to network time, and viceversa. In one implementation, the protocol is implemented in NIChardware, and is IEEE 802.1AS-compliant. In another implementation, onlythe hardware time stamping is applied in the hardware, and IEEE-802.1ASprotocol is implemented in software.

Extension of FireWire “Bridging”

The FireWire™ protocol allows for high-speed data transfer between twoor more devices. The protocol can maximally support sixty-three (63)devices on a single FireWire bus. FireWire bridging according to IEEE1394.1 allows the connection of multiple busses for expanding the numberof devices. The bridging component is described within the IEEE 1394.1specification as being comprised of (i) a serial bus bridge; (ii) twobridge portals (each with its associated PHY and link), (iii) queues(FIFOs) for asynchronous and isochronous subactions (which collectivelyform an implementation-dependent fabric between the two portals), (iv)cycle timers, (v) route maps, and (vi) configuration ROM.

In one embodiment, the present invention provides such an“implementation-dependent fabric” using an Ethernet AVB cloud. As usedherein, an AVB “cloud” refers to a collection of AVB devices thatsupport all the AVB protocols. Any legacy Ethernet device added to anAVB switch would terminate the cloud at that port. Accordingly, AVBdevices may exist which are not a part of the “cloud” structure (e.g.legacy AVB devices, etc.).

The exemplary fabric is adapted for compliance with IEEE 1394.1 bridgingrequirements, and comprises apparatus adapted to interconnect the 1394.1bridge portals that is capable of transferring any serial bus subactionfrom one portal to its co-portal. The fabric also supportsbidirectional, non-blocking transfer of asynchronous request subactions,asynchronous response subactions, and isochronous subactions.

Previous software implementations of FireWire-based audio have typicallyhad similar topologies to Universal Serial Bus (USB) “Host-to-device”models, due to the relatively inconvenient nature of physically wiringcomplex networks, despite FireWire device capabilities. By augmentingthe FireWire capabilities with Ethernet AVB, and the correspondingubiquitous Ethernet infrastructure, such limitations are advantageouslyremoved. Thus, while prior art implementations may implement a singlecentralized supervisory computer; the peer-to-peer nature of theFireWire/Ethernet AVB bus is not so limited. Hence, in another aspect ofthe present invention, the functionality between connection managementand datastream management is logically separated.

Such additional flexibility enables multiple additional use casescenarios. In one embodiment, a FireWire network with multipleconnection managers (e.g., computers) and one or more devices (e.g.,speakers, microphones, iPods, etc.) may have any number of convenientlyselectable interconnections and topologies.

In another embodiment, a connection manager (e.g. computer) may beseparate from a data source/sink (e.g., Home Theater Receiver, etc.).

In yet another embodiment, the merging and splitting of data sources canbe separated from connection management. Similarly, the connectionmanagement can be performed in isolation from the data being routedbetween the devices (e.g., data is not routed within the connectionmanager).

Methods—

Referring now to FIG. 1, a first embodiment of the generalized process100 for integrating an isochronous network of devices having differingnetworking protocols according to the present invention is described.

At step 102, a first isochronous network having at least one firstdevice capable of operating with at least a first and a second protocolinterfaces is initialized, and connects to an interconnection fabricwhich utilizes its second protocol interface. The initializationprocedures may comprise for example registration with a local or remotesoftware entity, such as a network daemon described hereinafter.

In one embodiment, the first protocol interface is an IEEE1394.1-compliant interface, and the second protocol interface is anEthernet AVB interface. The interconnection fabric comprises an EthernetAVB-compliant network cloud.

At step 104, an external device operating with at least a secondprotocol interface is initialized, and connects to the interconnectionfabric utilizing its second protocol interface. In one embodiment, theexternal or second device additionally comprises a first protocolinterface (not physically connected to the first device); the seconddevice is physically connected to a target isochronous device via itsfirst protocol interface (wherein the term “target” is applied forclarity rather than to indicate direction of data transfer). The targetdevice can also be part of the second device.

At step 106, the first device determines the existence of the seconddevice. In one embodiment, such identification is accomplished via asoftware entity, such as a software daemon. The identification isperformed local to either the first and or the second device. In analternate embodiment, such identification is performed at a third partyconnection management entity.

At step 108, the first device negotiates one or more isochronousparameters to connect with the second device. In one embodiment, suchisochronous parameters may comprise for example: (i) audio sampleformats, (ii) sample rates, and (iii) channel numbers, etc.

A source isochronous device in logical connection with the first devicevia the first device's first protocol interface receives (or transmits)an isochronous data stream to the target isochronous device (wherein theterm “source” is applied for clarity rather than as an indication ofdata transfer).

At step 110, the first and second devices provide a logical bridgebetween the first and second differing isochronous protocols. In oneembodiment, the management of the first and second devices andcorresponding source and target nodes is performed within a graphicaluser interface (GUI) or other such mechanism well known to those ofordinary skill in the computer arts.

At step 112, isochronous data is transferred via the logical bridge. Inone variant, the isochronous data stream transferred comprises at leastone stream of audio and/or video. Multiple source and target devices mayexist, each receiving and or transmitting at least one stream of audio,and or video.

Apparatus—

Referring now to FIG. 2, an exemplary apparatus 200 useful inimplementing the methods of the present invention is illustrated. Whilea specific device configuration and layout is shown and discussed, it isrecognized that other implementations can be readily implemented by oneof ordinary skill given the present disclosure. For example, variouscomponents may be divided and/or placed within other devices, integratedinto one physical form factor, etc.

The illustrated embodiment of the apparatus 200 comprises a device suchas a portable (laptop or handheld) computer, or audio/video capture, orsynthesis system capable of receiving or transmitting an isochronousdatastream across two or more differing protocols. In one exemplaryimplementation, the multi-lingual functionality is performed within adedicated processing device coupled to physical connectors for eachprotocol (e.g., a IEEE 1394 connector and an 802.3 Ethernet connectoraccessible on the back of the device), distributed throughout theequipment enclosure, as described in greater detail subsequently herein.

As shown in FIG. 2, the apparatus 200 comprises a processing subsystem202, operational memories 204, a first physical connector 206corresponding to a first protocol, and a second physical connector 208corresponding to a second protocol, and a power subsystem 210. In oneexemplary embodiment, the first physical connection corresponds to aFireWire (IEEE 1394) multi-pin interface (whether 4-pin, 6-pin, orotherwise), and the second physical connection corresponds to anEthernet AVB interface (e.g., RJ-45 connector). It will be appreciatedthat any number of different or similar physical connections (forexample, multiple homogeneous and heterogeneous ports) may be usedconsistent with the invention as well.

The processing subsystem 202 comprises a central processing unit (CPU)or digital processor, such as a microprocessor, digital signalprocessor, field-programmable gate array, or plurality of processingcomponents mounted on one or more substrates. The processing subsystemis tightly coupled to operational memory 204 which may include forexample SRAM, FLASH and SDRAM components. The processing subsystem mayalso comprise additional co-processors, such as a dedicated graphicsaccelerator, network processor (NP), or audio processor. A direct memoryaccess (DMA) subsystem (not shown) of the type well known in the art mayalso be utilized with the processor and memory in order to facilitatememory accesses. In one embodiment, a time scheduled Ethernet DMAhardware is used for scheduling Ethernet packets at the proper rate(e.g. 8000 packets per second). Normally, Ethernet DMA hardware is usedwhen streaming data or a group of descriptors. Ethernet DMA transmits assoon as the data arrives in the hardware queues. For Ethernet AVB,Ethernet data is queued in a priority queue with “time to send” values,such that the Ethernet DMA hardware is able to schedule packets out atthe proper rate and proper time.

The illustrated power management subsystem (PMS) 210 comprises acontroller for power delivery and battery management (if so equipped),and/or a plurality of discrete electrical components (not shown).Additionally, a chemical battery cell such as a Lithium Ion (Li-ion), orNickel Cadmium (Ni—Cd) battery provides power to the device apparatuswhen disconnected from a parent power source such as a 115 VAC walloutlet/transformer.

The illustrated mass storage subsystem 212 comprises an integratedcircuit memory for storing a computer readable program, and/or aplurality of discrete electrical components (e.g. motor, controller, andhard disks, etc.). Typical embodiments of such storage subsystems arehard disk drives common to the art. Other alternate embodiments may usenon-volatile solid-state memory, such as NAND/NOR FLASH, ROM, etc.

In certain embodiments, the device may further comprise one or more oftarget or source components. Such components consume or produceisochronous data streams. Typical embodiments may include: speakers 252,microphones 254, cameras 256, DVD and CD disk players 258, or monitors260. Such target/source components may be integrated within the device200, or stand-alone in nature (e.g., connected to the apparatus 200 viainterposed cabling, wireless links, etc.).

In another embodiment of the invention, the apparatus comprises anetwork switch or router adapted to perform data transport between twodevices (e.g., one operating according to a FireWire protocol, and oneoperating according to an Ethernet protocol). For example, in onevariant, the apparatus comprises a “super hub” that includes bothFireWire and Ethernet AVB ports on the hub, and which performs thetranslation to and from each protocol.

In still another embodiment, the apparatus comprises aremovable/portable “dongle” (e.g., adapter or converter). In onevariant, the dongle has a FireWire port on one end, and an Ethernet AVBport on the other. The dongle is plugged into the FireWire port orEthernet port on one device (or is otherwise connected to the portindirectly, such as via a male/female, male/male, or female/femaleinterconnection cable), and similarly connected at its other end to theother device. The dongle contains sufficient processing capability andsoftware to perform the protocol “translation” described elsewhereherein. It will also be appreciated that the dongle may be configuredfor “one-to-many” operation (e.g., one port of a first protocol, andmultiple ports for the other protocol).

Exemplary Implementation

The following software descriptions further illustrate one exemplaryembodiment useful in implementing a heterogeneous network of audiodevices for providing audio and/or video stream transfers, according tothe present invention. While this specific embodiment has functionalitydivided into kernel and user space operations, these distinctions shouldnot be construed as limiting as these components may be implemented bothin kernel space, and/or in user space.

Moreover, while the following description relates primarily focused onaudio data transfer, the invention is in no way limited to audio data,and in fact may support video and other multimedia data types. Videoformats supported may include for example (and without limitation) IEC61883-x based protocols such as IEC 61883-1, 61883-3, 61883-4, 61883-6,and 61883-7). See Appendix I hereto for a listing of some relevant“video” standards that may be utilized in conjunction with the methodsand apparatus of the present invention to facilitate, format and controlvideo delivery over different bearer protocols.

Various components are used in the illustrated embodiment to provide therequired functionality. Aspects of the functionality of these componentsare described below. The aforementioned components are also provided viaa computer program listing appendix entitled “AppleAS SOURCE CODE”disclosed in Appendix II, herein incorporated in its entirety.

Ethernet 802.1 AS Driver

AppleAS kext (Kernel Extension) is one embodiment of the 802.1ASEthernet driver. It implements the IEEE 802.1AS protocol and provides anAPI for mapping 802.1 AS grandmaster time to Host CPU time innanoseconds.

Referring now to FIG. 3, a software system 300 is shown, useful indescribing one exemplary software or protocol stack resident within aplurality of exemplary devices. As shown, each entity of the softwarestack 302 within each device communicates with the correspondingentities of other devices. A connection manager 304(AppleAudioNetworkingDaemon) is also shown. The entities comprise:AppleAudioNetworking 310, AppleIsochChannelMapper Kext (KernelExtension) 320, and AppleFireWireAVBBridge Kext 330. Two supplementalsoftware components are also utilized: AVCDescriptors Framework (notshown), IOFireWireMultiIsochListener 340.

The daemon (AppleAudioNetworkingDaemon) 304 is responsible forperforming device capability discovery, connection management andhandling device communications. The daemon sits above the various kernelextensions needed for performing channel mapping, bridging and audiostreaming, and the frameworks which provide device discovery, connectionmanagement calls and descriptor parsing.

The AppleAudioNetworking entity 310 provides application-levelmanagement via a graphical user interface for configuring devices andthe network of devices. The application entity receives connectionmanagement information from the daemon 304. The application entity 310is responsible for configuring kernel extensions, talking with devicesand performing local device discovery. AppleAudioNetworking handlesdiscovery and configuration aspects of the AppleFWAudio 312 driverwithin user space, rather than within the kernel. Drivers may be storedin operating system (OS) kernels to offload device management fromhigher-level software. AppleAudioNetworking handles audio devicemanagement functionality explicitly, as audio devices may notnecessarily be local to the AppleAudioNetworking software.

AppleAudioNetworking further provides, in the illustrated embodiment,support for AVB (Audio Video Bridging) devices using AVC (Advanced VideoCoding)-over-IP (Internet Protocol), as previously referenced herein.

AppleAudioNetworking is supplemented with three (3) components: (i)AppleFWAudio kext 312, (ii) FWAUserLib framework 314, and (iii)AVCVideoServices library 316. AppleFWAudio kext enables audio streaming.Devices are created and configured through the FWAUserLib framework withthe connection management being handled with the daemon (describedhereinafter). The AVCVideoServices library performs discovery ofFireWire and AVC-over-IP devices, reading of device configurations,performing device communication and connection management of AVC-over-IPdevices.

The IOFireWireMultiIsochListener 340 is a software function which allowsmultiple clients on one node to “listen in” to the same isochronouschannel. The IOFireWireMultiIsochListener does not restrict the numberof input isochronous contexts available. While theIOFireWireMultiIsochListener may perform basic formatting operations(e.g., modifying headers, address translation, etc.) to service variousclients, it does not alter the datastream itself. TheIOFireWireMultiIsochListener splits each isochronous channel to theAppleFWAudio, AppleFireWireAVBBridge (AFAB) Kext. AppleFWAudio, and AFABare critical to connection management.

The AppleFireWireAVBBridge (AFAB) 330 kext performs the bridging of thelocal FireWire bus to an AVB network/cloud. The AFAB uses the IEC61883/IIDC packet format of the AVBTP draft specification previouslyreferenced herein to encapsulate the FireWire isochronous packet. TheAFAB is a two-way bridge, capable of both transmitting and receiving AVBpackets. The AFAB may support any number of input and output streams,each of which may have differing channel counts. A user client enableslocal and or remote configuration of the AFAB.

The AVCDescriptors framework (not shown) is a Foundation-basedObjective-C framework that performs parsing of AVC device descriptorsinto an object-based hierarchy that can be easily used for getting andsetting properties of the descriptors. AVCDescriptors will accept eitherthe binary descriptor from the device or the appropriate dictionary fromAVCVideoServices. The AVCDescriptors may produce a binary or dictionaryversion of the descriptors suitable for AVCVideoServices or programminginto a device. The AVCDescriptors presents information necessary formanagement within a localized database, such that each FireWire node cantrack other FireWire, and Ethernet AVB members. In one embodiment, theAVCDescriptors is a software program for translating IEEE 1394 based AVCdevice descriptors into the industry standard XML format for storage ormodification. AVCDescriptors additionally supports conversion from theXML format to IEEE 1394 binary descriptor format. The XML outputs of theAVCDescriptors are used by the controller to discover the capabilitiesand parameters of the device, including such qualities as device name,names of plugs/streams, internal routing, etc. The binary outputs ofAVCDescriptors are used natively within connected IEEE 1394 compliantbusses.

FIG. 3A illustrates one exemplary packet structure useful with thepresent invention. The illustrated packet structure comprises threecomponents: a first header 352, a second header comprising one or moreisochronous parameters 354, and a payload 356. The packet, when beingbridged from one protocol to another, utilizes the first header 352 soas to comply with the “bridged to” protocol. Information is parsed fromthe parameters field 354, to determine any differences (e.g. samplerates) and or requirements to modify the payload. The payload 356 ispackaged for use at the destination.

While the packets share the same structure regardless of the source ordestination of the packet, it is appreciated that in certain embodimentsone or more elements of the packet structure may require modification toaccommodate differing endpoints. For example, packets from a first IEEE1394 compliant bus transmitted into an AVB cloud will have largeportions of the payload 356 filled with data when connecting to a secondIEEE 1394 compliant bus via the AVB cloud. Alternately, the same payloadmay be considerably smaller, when being transmitted to an AVB devicewithin the AVB cloud. Furthermore, packets from an AVB device in an AVBcloud to an IEEE 1394 compliant may have smaller payloads, and mayrequire padding with null data by an intelligent component, such as theAVB/FireWire bridge component.

In the illustrated embodiment, the first header 352 comprises anEthernet (IEEE Std. 802) header of the type well known in the art, whilethe second header comprises an IEEE P1722 header. The payloadillustrated is a FireWire packet payload of the type well known in theart. It will be appreciated, however, that other packet headers andstructures (as well as different protocols) may be used consistent withthe invention.

FIG. 3B is a high layer representation 360 of the software systemcomponents; as shown, the system is separated between user-land(applications and APIs) 362 and the kernel (drivers) 364.AppkFireWireAVB Proxy 366 is the controlling software component thatsets up the Ethernet to FireWire mapping and instantiates the componentsneeded for the bridging of protocols.

FIG. 3C is a graphical representation of one embodiment of an exemplaryprotocol stack (kernel space) 370 implementing the heterogeneousprotocol data transfer functionality of the present invention. Theexemplary protocol stack includes the additional components: AppleAS371, AppleMAAP 372, Apple1722Ethernet 373, Apple1722Dispatcher 374 andAppleFireWireAVBBridge. IONetworkFamily 375 and Ethernet Drivers 376 arepre-existing Ethernet protocol stack components; similarly the FireWireStack 374 uses existing FireWire stack in the current system.

In the exemplary embodiment, the current FireWire stack, Ethernet stack,user-land API and associated software components are combined inaccordance with one or more aspects of the present invention.Specifically, the present invention enables user-land softwareoperation, regardless of physical link characteristics. The isochronousstream data may be received from either the Ethernet or IEEE 1394 link.Moreover, the existing applications and APIs running on the systemcannot directly access the physical links; thus higher level softwareremains unaware of link specific operation. The separation of user spacefrom kernel space seamlessly provides isochronous data to the upperlayer software without requiring configuration for either Ethernet AVBof FireWire protocols. Consequently, existing FireWire applications,like “iMovie”, can run without requiring modification.

FIG. 3D is another graphical representation 380 of various components ofthe example protocol stack of FIG. 3C, and their interrelationships. Asshown in FIG. 3D, components added in the kernel space include: (i)AppleAVBInterface; (ii) AppleAS (802.1AS time synchronization) 371;(iii) AppleVirtualAS (802.1AS time synchronization for unsupportedhardware) 381; (iv) AppleMAAP (dynamic allocation of multicast MACaddresses) 372; (v) Apple1722Dispatcher (routes AVB frames betweenmultiple clients) 374; (vi) Apple1722Client (abstract client class) 382;(vii) Apple1722Ethernet (client subclass for Ethernet interface); and(viii) AppleFireWireAVBBridge.

FIG. 3E is a graphical representation 390 of one embodiment of anexemplary protocol stack (user space) implementing the heterogeneousprotocol data transfer functionality of the present invention. Theexemplary user space additions are two (2) peer entities:AppleAudioNetworking 391 and AppleAVBFireWireProxy 392. TheAppleAudioNetworking software module is resident to the Ethernet AVBdevice, whereas the AppleAVBFireWireProxy software module communicateswith the Firewire device. It should be noted that both modules may ormay not be co-located within the same device, depending onimplementation, etc.

FIG. 3F is a block diagram of one embodiment of a software architecture395 employing a proxy for interfacing between a first device and varioussoftware processes on the same or different device. As shown in FIG. 3F,the kernel space and user space components of FIGS. 3C and 3E,respectively are used to bridge between a FireWire network, and anEthernet AVB network, via the proxy software entity.

Referring now to FIG. 4, one exemplary heterogeneous community 400 ofthe aforementioned devices useful in illustrating the methods andapparatus of the invention is described. As shown in FIG. 4, device 200Ais physically interconnected to another device 200B via a common bus 406(e.g. IEEE 1394), and logically interconnected via the aforementionedsoftware functions. Each group of devices negotiates their internaladdressing within a localized network. Bridging portals are deviceswhich “bridge” from the localized network to an external device 200C(e.g., another device of similar or differing nature). Bridging portalsprovide connection 404 to a fabric 402, wherein the fabric must becapable of transferring any serial bus subaction from the bridgingportal to its destination device (e.g. co-bridging portal, externaldevice, etc.). The localized network may utilize a protocol (e.g., IEEE1394.1), which is different than the interconnecting fabric (e.g.Ethernet AVB).

As previously described herein, the “fabric” of the present embodimentmay be conceptualized as a set of FIFOs that support bidirectional,non-blocking transfer of asynchronous request subactions, asynchronousresponse subactions, and isochronous subactions. The fabric could bemodest in geographical extent, as when the bridge portal and externaldevice are located within a single enclosure. Conversely, the fabriccould be physically extensive, as could be the case if a bridge's portalwas located in separate room from the external device.

In one exemplary embodiment, the devices 200 are FireWire devicescompliant with IEEE 1394, and the fabric 402 is an EthernetAVB-compliant “cloud”. As shown, an IEEE 1394.1 compatible portal 200Ais on at least one side of the Ethernet AVB network, and employs AVCcommand interpreters in the portals to allow existing FireWire softwareto “see” FireWire and Ethernet AVB devices (i.e. 200C, 200D) that arenot physically connected to the local FireWire bus via the Ethernet AVBconnection 404.

In yet another exemplary embodiment, a pair of bridging portals (200Aand 200C) may bridge two separate busses (406) having a first protocol,via a fabric (402) having a second different protocol with suitableisochronous properties. Such bridging portals are responsible forconverting the information on one bus for transfer to the co-bridgingportal on the other bus. The connection fabric between portals could bean internal bus, system bus, or any other interconnection readilyunderstood by those skilled in the electronic arts. If the connectionfabric between portals is private, the portals may send packets via theconnection fabric without any additional processing (e.g. encryption).Certain interconnection fabrics are desirable for varying purposes; forinstance, an Ethernet AVB network between bridging portals can enablesignificant geographic distance between a first and second network. Ifthe fabric is an Ethernet AVB network, then the portals could be putanywhere on the Ethernet AVB cloud and still function correctly.

Example Use Scenarios

In a first example, the Assignee manufactures and releases a newcomputer that has no FireWire ports but does include the new EthernetAVB hardware. With a small dongle that implements the FireWire to AVBprotocol conversion described in this patent, the user can connect theFireWire audio device to the dongle and then connect the dongle to thenew computer via the Ethernet jack. The FireWireAVB proxy software onthe computer will then connect to the FireWire audio device as if it isnow an AVB audio device. The AppleEthernetAudio driver will enumerateand discover the device, presenting it to the Audio sub-system. Audioapplications adapted to operate with FireWire type devices will operateseamlessly with the new computer. The bridging “dongle” willtransparently enable the software to see the FireWire Audio device as ifit was directly connected to a FireWire port.

In another aspect of this invention, a first computer can physicallyincorporate the “dongle” that is mentioned above to enable play throughoperation by a second computer on a computer network. The first computerwith both FireWire and AVB compliant Ethernet hardware can act as abridge between FireWire and Ethernet AVB. The software on the firstcomputer would provide an “AVC FireWire device sharing mode” to thesystem software so that any computer (e.g. second computer) on thenetwork could see the FireWire device attached to the first computer. Asecond computer on the network may then connect to the first computerover the Ethernet AVB network and use the services provided by theFireWire device. In this mode, an unmodified AVC FireWire applicationlike iMovie running on the second computer, could operatively utilizethe FireWire device resident to the first computer; iMovie could operateas if it was directly connected to the FireWire device.

The following example user scenarios (FIG. 5A-D) illustrate somepossible application environments enabled by the methods and apparatusof the present invention. These scenarios are only exemplary, and theinvention is in no way limited thereto.

With respect to FIG. 5A, a regular user (Jack) is a Macintosh™ (“Mac”)computer user and has been for many years. He owns a FireWire audiodevice (FAD) 502. He has been using the Mac OS X Leopard™ operatingsystem for a long time, and has just upgraded to the latest Mac OS X,FatCat™. Jack plugs in his FAD, starts Logic Pro, which is his digitalaudio workstation software (DAW) and sets it to use his FAD. He thenproceeds to do what he has previously done with his DAW.

Mac OS X FatCat includes a new FireWire audio architecture supportingnetworking, and has added support for the new AVB specification; howeverJack is not interested in any of these features and has never launchedthe AppleAudioNetworking application. None-the-less, he expects his FADto behave exactly the same as it always has in previous versions of MacOS X.

Referring now to FIG. 5B, a studio user (Bob) is a sound engineer at arecording studio. He uses Mac OS X as his platform of choice, and hasmany FADs around his studio. Bob has recently switched to the new Mac OSX FatCat because he has heard about the new FireWire audio networkingfeature.

Bob launches the AppleAudioNetworking application, and connects his allhis FADs (which comprise two 2-channel FADs and 3 18-channel FADs) tohis MacPro. He also connects several other Macintoshes to the FireWirebus to act as channel mappers. He configures his local Macintosh to havea 30 channel input, and output CoreAudio device consisting of three10-channel input streams and one 42-channel output stream. He connectsthe 3 input streams to 3 of his 18 channel FADs. He creates a channelmapper on one of the remote machines that takes a 42-channel inputstream, and outputs three 10-channel streams. He connects the inputstream of the mapper to the output stream of his MacPro, and the 3output streams to his 18-channel FADs. Bob also creates a channel mapperon another of his remote machines that takes a 42-channel input streamand outputs 6 2-channel streams. He connects the input stream of themapper to the output stream of his MacPro, and the output streams toeach of the 2-channel FADs. He adjusts the mapping so that the 2-channelFADs streams are connected to the last 12 channels rather than the first12 channels. Bob then saves the configuration so that he can use itagain.

Bob opens up the Logic (DAW) and configures it to use his new 30-channelinput and 42-channel output device. He sets up appropriate mixes on thelast 12 channels for the 2-channel FADs to be used as stage monitors,and sets up appropriate mixes on the first 30 channels. Bob then startshis recording session. When Bob has finished his recording session, andcopied his audio, he turns off all of his equipment.

The next day Bob comes back to continue recording with the same setup.He turns on all of his equipment, starts his DAW and commences the day'sactivities.

Referring to FIG. 5C, a live performance user (John) works at a concerthall. They have recently upgraded their system to use new high-speedEthernet-based AVB and FireWire devices and Mac OS X FatCat as thecontrol and configuration platform. The control room is equipped withseveral MacPro devices running various software applications needed tocontrol their concert hall, and to run the AppleAudioNetworking softwareto configure their sound system.

The concert hall is fitted with AVB-equipped speakers rigs all beingwired back to a central AVB cloud synchronized to a class-Aspecification. The MacPro devices in the control room, as well asseveral under the stage, are also connected to the live sound AVB cloudas well as a secondary communications cloud. A central AVB based mixingboard 510 is provided in the control room, which can have configurationssaved and loaded by a computer over the AVB cloud.

A new concert is being planned and setup in the hall. John's task is toset up the sound system. He sits down at the main configurationcomputer, opens AppleAudioNetworking, and loads a copy of the cleandefault sound network configuration. He adjusts the configuration forthe particulars of the concert. One of the special features of thisconcert is a FireWire-based sound effects box which is triggered by theaudio. This box is connected to one of the MacPro devices under thestage. The technicians on stage have already set this up, and so a newdisplay icon has appeared in AppleAudioNetworking to represent thisdevice. John needs to connect this to the mixing board.

While John was configuring the sound system routing, someone else wassetting the mixing board configuration to add an extra stream for thesound effects box. They pass this file to John, who uploads it to themixing board via a vendor plug-in in AppleAudioNetworking. John now hasan extra output stream on the mixing board to connect to the specialeffects box. John connects the new output on the mixing board to theinput of the special effects box, and AppleAudioNetworking establishes aconnection between the two via a bridge on the MacPro to which thespecial effects box is connected. John then saves this configuration forthe concert.

On the day of the concert, John loads up the saved configuration andthen runs through the usual pre-concert checks.

Referring to FIG. 5D, an experimenter (Eve) is an experienced Mac OS Xuser. She has just upgraded to Mac OS X FatCat. She has noticed a newfeature of the operating system (audio networking). She has beenexploring her system, and has discovered the AppleAudioNetworkingapplication. She launches the application and is presented with thecurrent configuration of her system. She has no FireWire or AVB devices,so all she sees is an icon for her local Mac. She opens the README linkto find out more information about what she can do with thesystem/software.

She reads that she can set up multiple Macs on the same network to talkto each other, and send audio directly between the machines. Since shehas two Macs running Mac OS X FatCat, she decides to set up an audionetwork to play with. She enables multi-Mac support on each of hermachines, since it is a private network which nobody else can connectto, she decides to not enable password authentication.

On both Macs she creates a 2-channel AVB device. On one of her machinesshe connects the input of each machine to the output of the othermachine. On one machine she opens up “System Preferences” and sets theAVB device as the output device. She then opens iTunes™ and startsplaying her music. On the other machine, she enables pass-through fromthe AVB device to the built-in speakers, and her music begins playingfrom her speakers.

Wireless Variants

In another aspect of the invention, the aforementioned protocols used onthe various communicating devices may comprise wireless protocols suchas for example WLAN, PAN, or WAN/MAN protocols.

Wired operation may statically reserve resources to enable operation.For instance, Ethernet AVB requires each node between the source andtargets to reserve resources for datastream transmission, thus providinga bandwidth, and latency guarantee. Transmission and reception of datais relatively reliable for wired devices; however, wireless devices mayfade in and out of service, causing considerable complication. Awireless linkage in combination with a wired link may fade outunexpectedly, leaving unused reserved resources on the wired network.Methods and apparatus for bridging wireless/wired devices must alsoprovide for “clean up” operations.

Under one embodiment, wireless operation of one or more components ofthe aforementioned heterogeneous networks is envisaged. In addition toproviding a bridging access from a first wired protocol to a secondwireless protocol, concurrent monitoring, diagnosis and re-routing ofwireless/wired links are desired to minimize unnecessary resourceutilization during a “fade out”. In one variant, each of the bridgingdevices, the target or the source may transmit a link condition signalrelating current status of the isochronous stream. A bridging elementwithin a heterogeneous network may monitor the reliability of one ormore wireless links, and transmit feedback to the source device, thusenabling the source device (and any associated wire line “hops”) tothrottle their reserved resources accordingly.

In another embodiment of the wireless/wired invention, a bridgingelement within a heterogeneous network may register a relativeestimation of wireless robustness for use with the connection managementsoftware. In one variant, the connection management software maymaintain an entry for each wireless device, related to relative wirelessdata rate. Such an entry may be e.g., a relative measurement of biterror rate (BER), signal to noise (SNR), or any of the other plethora ofuseful link-related measurements commonly known to those skilled in thetelecommunications arts. In another variant, such an entry mayadditionally include a total number of subscribers actively connected toa datastream, to accommodate the requirements of broadcast and ormulticast operation. For example, one or more subscribers may drop offwithout adversely affecting the experience of other broadcastsubscribers.

In yet another embodiment of the wireless/partially wireless invention,a bridging element within a heterogeneous network having a wirelesssource and destination may continuously poll each wireless link for tomodify its operation. In one variant, the bridging element may regularlyinsert, re-process or sniff packets being received and transmitted todynamically size the reserved resources to only what the weakest linkmay serve. Alternatively, the bridging element may perform suchmonitoring to dynamically size the reserved resources to only what thestrongest receiving link may serve (as applicable within a broadcast ormulticast situation).

In yet another embodiment of the wireless/partially wireless invention,a bridging element within a heterogeneous network may receive linkupdates from one or more target device attached to a bus on the secondprotocol. For example, a bridging element connecting two differing wireline protocols may receive notification from one such protocol that awireless linkage downstream has failed (e.g., a device on a wirelesshub, which is connected to the bridging portal via wire line).Alternatively, a bridging element connecting a wireless protocol to awired protocol may receive notification that a wireless link downstreamof the wired protocol has failed (e.g. an Ethernet AVB cloud connectinga wireless device on a bridging node to a wireless LAN, etc.

A channel mapping element may also be utilized consistent with theinvention. Under one embodiment, the mapping element adaptively resizeschannels based at least in part on the wireless channel reception. Forexample, one or more channels of channel mapping functionality may bepreprocessed based at least in part on the expected wireless linkquality.

Other implementations and variations of the foregoing features will beappreciated by those of ordinary skill given the present disclosure.

Business Methods and Models

In another aspect of the invention, various business models and methodsof doing business relating the aforementioned heterogeneous networks areenvisaged.

In one aspect, the ability to obviate one or more ports on a device isinherently less expensive. For example, a device manufacturer or serviceprovider can support similar features to their preexisting products orservices with a smaller bill of materials (BOM) for the correspondinglyreduction in components (e.g. port connections, driver hardware, etc.).Furthermore, replacement of high cost port solutions (e.g. FireWire)with lower cost port solutions (e.g. Ethernet AVB) would alsoadvantageously work to reduce manufacturing cost.

In another aspect, an adapter device capable of bridging between a firstnetwork, to a pre-existing device having a second network connectiontype could be manufactured and sold, so as to maintain backwardcompatibility. Consistent support of backward compatibility is generallyconsidered in customer's determination of price; and customers willostensibly be willing to pay more for consumer electronics devices whichare supported through time, rather than made obsolete. Furthermore, themanufacture and sale of adapter devices (commonly referred to in thearts as a “dongle”) is also profitable, in some cases providingopportunities for third party licensing fees.

In one embodiment, a device capable of both connection operation andstreaming operation may require a software patch sold after purchase, toenable one, or both features. In a related embodiment, connectionmanagement is a relatively sporadic software function, whereas streamingdata has specific requirements on the data path. These differences maybe leveraged in manufacturing such specialized devices.

It will also be appreciated that the methods and apparatus describedherein, by allowing for isochronous data networking spanning varyingprotocols and networks, and limited software modifications to extantinfrastructure and devices, also provide an intrinsic cost benefit overprior art isochronous data networking technologies. Specifically, byobviating the expense of infrastructure through reuse of existingnetworking technology, some of the cost and complexity associated withsuch isochronous networking can be avoided, and customer systems madesimpler and “thinner” in terms of capability.

Moreover, greater levels of connectivity between devices can beachieved, even when the pervasiveness of certain types of physical ports(e.g., 1394) has decreased with time.

It will be recognized that while certain aspects of the invention aredescribed in terms of a specific sequence of steps of a method, thesedescriptions are only illustrative of the broader methods of theinvention, and may be modified as required by the particularapplication. Certain steps may be rendered unnecessary or optional undercertain circumstances. Additionally, certain steps or functionality maybe added to the disclosed embodiments, or the order of performance oftwo or more steps permuted. All such variations are considered to beencompassed within the invention disclosed and claimed herein.

While the above detailed description has shown, described, and pointedout novel features of the invention as applied to various embodiments,it will be understood that various omissions, substitutions, and changesin the form and details of the device or process illustrated may be madeby those skilled in the art without departing from the invention. Theforegoing description is of the best mode presently contemplated ofcarrying out the invention. This description is in no way meant to belimiting, but rather should be taken as illustrative of the generalprinciples of the invention. The scope of the invention should bedetermined with reference to the claims.

APPENDIX I Other Standards and Technologies

IEC 618834

IEC 61883-1 (“Consumer audio/video equipment—Digital interface—Part 1:General”—February 1998), incorporated by reference herein in itsentirety, is a standard that describes, inter alia: (i) isochronous PlugControl Registers; (ii) Connection Management Protocol (CMP); (iii)Function Control Protocol (FCP); and (iv) Common Isochronous Packet(CIP) headers. It is useful for the transport of isochronous data whenusing AV/C, DVC, MPEG, or AMP.

AV/C General Specification

AV/C General Specification (Accepted by 1394 TA (version 4.2), andincluding 1998010—“Enhancements to the AV/C General Specification 3.0”,1998001—“AV/C Digital Interface Command Set General Specification”, and1996002 “AV/C Digital Interface Command Set”) each incorporated byreference herein in its entirety, defines inter alia general commandsused to control consumer audio/video electronics. It utilizes 1394 Unitarchitectures, and is useful for implementation of audio/video devices,and for software driver development.

MPEG4 Over 1394

MPEG4 over 1394 is not yet standardized; a study group is investigatingthe need/demand for a specification to transport MPEG4 (including H.264)over 1394, and identifying which parts of MPEG4 are applicable. Thegroup is also discussing strategies for a specification (i.e.,encapsulating in MPEG2-TS over 61883-4, or transport MPEG-4 in ‘native’form over 1394). This standard (when finalized) would be applicable forall devices sending MPEG4 streams over 1394.

IEC 61883-6

IEC 61883-6 (“Consumer audio/video equipment—Digital interface—Part 6:Audio and music data transmission protocol”—February 1998), incorporatedby reference herein in its entirety, is a standard that describesAudio/Music Transport Protocol across 1394. It is useful for devicestransporting formatted Audio or Music streams over 1394.

IEC 61883-2

IEC 61833-2 (“Consumer audio/video equipment—Digital interface—Part 2:SD-DVCR data transmission”—February 1998), incorporated by referenceherein in its entirety, is a standard that describes SD-DVCR TransportProtocol across 1394. It is useful for devices transporting SD-DVCR over1394.

IEC 61833-3

IEC 61883-3 (“Consumer audio/video equipment—Digital interface—Part 3:HD-DVCR data transmission”—February 1998), incorporated by referenceherein in its entirety, is a standard that describes an HD-DVCRTransport Protocol across 1394.

IEC 61883-5

IEC 61883-5 (“Consumer audio/video equipment—Digital interface—Part 5:SDL-DVCR data transmission (TA4)”—February 1998), incorporated byreference herein in its entirety, is a standard that describes SDL-DVCRTransport Protocol across 1394.

IEC 61883-4

IEC 61883-4 (“Consumer audio/video equipment—Digital interface—Part 4:MPEG2-TS data transmission”—February 1998), incorporated by referenceherein in its entirety, is a standard that describes MPEG TransportStreams (TS) (including DVB TS) across 1394.

IEC 61883-7

IEC 61883-7 (“Consumer audio/video equipment—Digital interface—Part 7:Transmission of ITU-R 130.1294 System B”—February 1998), incorporated byreference herein in its entirety, is a standard that describes MPEGTransport Streams (TS) for DSS (not quite the same as standard MPEG-2)across 1394.

TA 1998005

TA 1998005 (“AV/C Tuner Broadcast System Specification—Digital VideoBroadcast (DVB)—1998), incorporated by reference herein in its entirety,is a standard that describes AV/C control enhancements for Digital VideoBroadcast (DVB) video tuners. It is useful for devices doing DVB videotuning controlled across 1394.

What is claimed is:
 1. Apparatus configured to manage connectivity of aheterogeneous fabric, comprising: an interface to the heterogeneousfabric having a first protocol associated therewith; a processor; and acomputer readable storage medium with at least one computer programstored thereon, the at least one computer program configured to, whenexecuted on the processor, cause the apparatus to: responsive to adevice having a second protocol associated therewith and different thanthe first protocol being coupled to the heterogeneous fabric, identifyone or more device capabilities; store the one or more devicecapabilities; and responsive to a request from the device for a dataconnection to a target device, provide the stored one or more devicecapabilities to the target device; wherein the device and the targetdevice initiate the data connection via the heterogeneous fabric withoutfurther intervention by the apparatus.
 2. The apparatus of claim 1,wherein the heterogeneous fabric is configured to support isochronousand asynchronous data traffic.
 3. The apparatus of claim 2, wherein thedevice and target device exchange isochronous data.
 4. The apparatus ofclaim 3, wherein the target device is configured to operate in accordwith a third protocol, the third protocol different than the secondprotocol.
 5. The apparatus of claim 3, wherein the target device isconfigured to operate in accord with the second protocol.
 6. Theapparatus of claim 1, wherein the initiated data connection comprises anaudio stream.
 7. The apparatus of claim 1, wherein the second protocolcomprises an IEEE 1394-compliant protocol.
 8. The apparatus of claim 7,wherein the first protocol comprises an IEEE 802.11-compliant protocol.9. A method of managing connectivity over a heterogeneous fabric, themethod comprising: receiving an indication of one or more capabilitiesassociated with a first device, the first device having a first protocolassociated therewith and the first device being coupled to theheterogeneous fabric; responsive to the indication, storing at least onedevice capability associated with the first device; responsive to areceived request for a connection to a target device, providing the atleast one stored device capability to the target device; wherein thefirst device and the target device initiate the data connection via theheterogeneous fabric without further outside intervention; and whereinthe target device has a second protocol associated therewith.
 10. Themethod of claim 9, wherein the heterogeneous fabric is configured tosupport at least isochronous traffic and asynchronous traffic.
 11. Themethod of claim 9, wherein the provision of the at least one storedcapability at least in part enables one or more messages to be sent fromthe first device to the target device.
 12. The method of claim 11,wherein the target device is associated with a second protocol, thesecond protocol being different from the first protocol.
 13. The methodof claim 12, wherein the one or more messages are sent in compliancewith at least one of the first and second protocols.
 14. The method ofclaim 13, wherein the one or more messages are formatted for theheterogeneous fabric by an interface of the first device.
 15. The methodof claim 9, wherein the heterogeneous fabric is associated with one ormore network daemons.
 16. The method of claim 15, wherein at least oneof the first and target devices is configured to register with at leastone of the one or more network daemons.
 17. A non-transitorycomputer-readable medium configured to manage connectivity of a datafabric, an interface to the fabric having a first protocol associatedtherewith, the computer-readable medium containing instructions which,when executed by a computerized device, cause the computerized deviceto: responsive to a device having a second protocol associated therewithand different than the first protocol being coupled to the data fabric,identify one or more device capabilities; store the one or more devicecapabilities; and responsive to a request from the device for a dataconnection to a target device, provide the stored one or more devicecapabilities to the target device; wherein the device and the targetdevice initiate the data connection via the data fabric without furtherintervention by the computer.
 18. The non-transitory computer-readablemedium of claim 17, wherein the data fabric comprises a heterogeneousfabric configured to support isochronous and asynchronous data traffic.19. The non-transitory computer-readable medium of claim 17, wherein theone or more messages are formatted for the data fabric by an interfaceof the first device.
 20. The non-transitory computer-readable medium ofclaim 17, wherein the data fabric comprises a heterogeneous fabricassociated with one or more network daemons.